Margaret McGuckin, from Survivors and Victims of Institutional Abuse (Savia), said the letter was "too little, too late".

"It won't wash with us, the damage has already been done," she said.

"If the Pope is anyway genuine about this statement, if he is sorry about these atrocities, let him agree to an inquiry in the north of Ireland."

'Address abuse issue'

Archbishop Martin said he would be "surprised" if the Pope did not meet victims of abuse during his 36-hour visit.

"I would like to think that the Pope will meet with survivors of abuse but will also address this issue in some way during his presence among us.

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The Pope's Irish visit could lead people to rekindle their faith, says Archbishop Martin

"I'm not sure what his words will be and I'm not sure that a simple apology is what survivors of abuse want.

"They themselves are on record in recent days as saying they want action.

"They say they want to know that the Church accepts that abuse within the Church was systemic, that it was facilitated and that this will happen no more."

The Archbishop added: "If he expresses an apology, it needs to be more than 'we're sorry'."

'Church repudiates homophobia'

Asked if same-sex couples would be welcome at the papal events in Ireland next week, Archbishop Martin said that the Catholic Church had a "very clear teaching" about marriage, family and sexuality.

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Same-sex marriage will be discussed during the Pope's visit, according to Archbishop Martin

"At the same time, the Catholic Church welcomes and understands people where they are at - it repudiates homophobia," he added.

He said the Church would reject claims by critics who say that its teaching breeds homophobia.

Archbishop Martin added that it was "a very sensitive issue" and would be addressed at the World Meeting of Families.

There is speculation that Pope Francis may be considering a specific visit to Northern Ireland, perhaps as soon as next year.

Archbishop Martin said he hoped that would happen.

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Any papal visit to Northern Ireland could include a stop at St Patrick's Cathedral in Armagh

"I really did push hard to try to encourage the Holy See that the holy father would make a visit north of the border.

"I really feel that the time is right for it now and I think Pope Francis would love to come."

'Be open and listen'

So why not during next week's visit to Ireland?

"In some ways I now realise that a visit to Northern Ireland, particularly with our history and with all that we've been through, is going to require a dedicated time.

"Pope Francis, even though he's not coming to Northern Ireland on this occasion, I'm hoping that he might say something to us in our particular situation here in Northern Ireland about our peace and what we have done and maybe affirm us in the progress we have made."

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The last papal visit to Ireland was by Pope John Paul II in 1979

Archbishop Martin said his life "changed" when, as an 18 year old, he saw Pope John Paul II in Drogheda in 1979.

"The following year I went off to study for the priesthood," he said.

"I would say to Catholics - be open, listen to what Pope Francis has to say.

"Perhaps this a moment to rekindle your own personal faith in Jesus Christ, our saviour."